The present invention relates to an eccentric screw-type pump consisting of a pump section with a tubular pump casing, with a stator cladding including a pump cavity formed in correspondence with a two-thread or multithread screw, with a charge casing and with a drive system and with a screw-type rotor that is connected to a driving shaft by way of a flexible shaft, wherein the flexible shaft is connected by its two ends via rigid coupler elements to the rotor and the driving shaft.
EP 0 657 649 B1 discloses a pump structure in which a flexible shaft presents a long radial distance from the intake housing. In this case, the flexible shaft is connected to the driving shaft by a screw connection and to the rotor head via a coupler transmitting the torque via a pin. The pin is covered by a coupling sleeve adapted to be pushed over the rotor head. The product supplied to the intake housing is caused to arrive in the rotor/stator zone merely by the introduced pressure and by the suction power of the pump.
DE 15 53 201 A1 discloses an eccentric screw-type pump wherein a rigid connecting shaft is disposed between a screw-type rotor and a driving shaft. A driving sleeve is seated on the drive-side end of the connecting shaft for holding a non-supported screw and causing this screw to rotate. The screw obtains a certain running smoothness and inherent stability by the provision that it is permanently supported on the inner wall on the intake housing.